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SAN2202 APPLICATION NOTE
SINGLE CHIP “SPEAKERPHONE” WITH 8 - OHM LOUDSPEAKER AMPLIFIER
1 Scope
This application note describes a low-cost add-on circuit for driving an 8Ω-Loudspeaker to get a simple loudhearing (“Speakerphone”) Telephone.
To possible ways of supplying the amplifier are shown: SAN2202a: SAN2202b: Amplifier supply in shunt
transistor path Amplifier supply by power extraction circuit (SAN3020)
It can be added to any SA253x application without interfering with PTT-relevant parameters, like AC-impedance, Sidetone cancellation or DC-mask.
2 Key Features • Low cost additional circuit enables use of loudhearing function • Full duplex “handsfree” operation via handset micro...